The United Nations should set up a commission to look at the conflicts between privacy and freedom of expression on the internet because the issue is global, the Council of Europe's head of human rights has urged.

Attending a debate on media freedom organised by the anti-censorship organisation Article 19, Thomas Hammarberg, the Council of Europe's commissioner for human rights, said politicians needed to become more engaged in the problem.

Unesco, he thought, had dodged responsibility and its interest had proved "disappointing" since it is, technically, the relevant legal UN body. In contrast, Hammarberg praised the work of the UN special rapporteur on freedom of expression, the Guatemalan lawyer Frank La Rue, who earlier this month warned that fearful governments were increasingly restricting the free flow of information online.

"The time has come for politics to pay attention to internet media," Hammarberg insisted. "These kind of clampdowns which we have seen in China must be prevented.

"We would like to see a discussion about international regulation which would filter out porn or incitement to war and hatred. The time has come to begin to find the right way to regulate it with the protection of freedom of expression. Some governments have restrictions and others are letting it become like the wild west.

"When I discuss freedom of expression with governments I notice there's a problem here. We need to have a serious discussion about this. We need to protect the diversity of media. The tendencies in some countries are very restrictive.

"There should be a special commission appointed to work on this appointed by the UN because the problem is so global nowadays. There's a need for an international dimension. Most of the sites are run by private companies but the regulations are directed towards governments. It's complicated."

Of the use of superinjunctions in the UK courts, Hammarberg, who has been a Swedish diplomat and was formerly secretary general of Amnesty International, observed: "That means you are not allowed to say there's even been a case about this and I believe that's a violation of expression."

He welcomed the UK justice secretary's determination to reform the European court of human rights in Strasbourg. "Ken Clarke really knows the European system well," Hammarberg said. "I think it could be a great contribution. There are some problems of function of the court. There are 50,000 applications a year and it's overloaded. There's a need for further really radical reforms. He could help with that.

"I hope the UK authorities would go into this [positively] and not try to tear it down. Any discussions about leaving would be damaging, not only to the people who want to use the court but to other structures of Europe. Why should Russia and Turkey remain in [the Council of Europe] if not even the UK stays?"

Agnes Callamard, the executive director of Article 19 who helped organise the conference in London, also deplored the eagerness with which some websites complied with requests to remove material.

"Internet service providers, Facebook and Google should not be liable for what their users are doing. They are not publishers but like telephone companies [in relation to callers]," she said.

"There's an established practice of internet sites being asked to filter or block contact. Normally it's easier to comply with requests. There's a lot of evidence that they are filtering and blocking far too easily.

"We say there should be no censorship outside the legal process. So people can argue whether it's breaking the law or libellous. Censorship should not be an easy decision to take.

"During the Egyptian uprising there were accounts online of police torture and beatings which were taken offline ... and that was on the grounds of violence and taste."